The Daily Telegraph reported that there could be a good reason why the television presenter Richard Hammond, who suffered a brain injury in a high-speed car crash, developed a liking for...

The Daily Telegraph reported that there could be a good reason why the television presenter Richard Hammond, who suffered a brain injury in a high-speed car crash, developed a liking for celery afterwards. It said that researchers have found that “brain inflammation of the kind he suffered is reduced by luteolin - a compound found in celery, green pepper, parsley and chamomile”.

The newspaper states that the findings suggest that “luteolin may, in proper doses, help not just brain inflammation, but also patients suffering from brain illnesses such as Alzheimer's or Creutzfeldt-Jacob disease”. The study was carried out in mice and the researchers point out that the effects of luteolin in humans “is still not fully understood”.

The important thing to note is that this study was carried out in mouse brain cells and live mice who were exposed to a substance found in bacteria so that they would experience an inflammatory response. It did not look at the effects of luteolin on a traumatic brain injury, or in mice who have conditions similar to Alzheimer's or Creutzfeldt-Jacob disease. It is too early to suggest that luteolin might have a beneficial effect in humans with these conditions.

Where did the story come from?

Dr Saebyeol Jang and colleagues from the University of Illinois at Urbana–Champaign carried out the research. The study was funded by the National Institutes of Health, and the luteolin was donated by Synorex Co.

The study was published in the peer-reviewed scientific journal: Proceedings of the National Academy of Sciences of the USA.

What kind of scientific study was this?

In this experimental laboratory study, the researchers looked at the effects of luteolin, a chemical found in celery and green pepper, on mouse brain cells grown in the laboratory, and on mice.

Luteolin had been shown to reduce the production of certain molecules that promote inflammation in the body. If excessive amounts of these molecules are produced by immune cells in the brain, they can cause damage to the brain and behavioural problems.

In order to promote an immune response, and so an inflammatory effect could be observed, the researchers treated mouse brain immune cells with a molecule found on the outer wall of bacteria (lipopolysaccharide – LPS).

They then added luteolin to some of the cell cultures and looked at the effect the luteolin had on the production of a molecule called IL-6, which is associated with inflammation. They were also interested in how luteolin might cause this effect.

The researchers then looked at the effects of luteolin in live mice. They put luteolin in the drinking water of a group of mice for 21 days, and then injected them all with LPS. They also kept a control group of mice who were given water without luteolin in it. They then examined the effects that luteolin had on IL-6 production in the brain and the blood.

What were the results of the study?

The researchers found that luteolin reduced the amount of the inflammatory molecule IL-6 the brain immune cells produced when were exposed to a bacterial molecule (LPS). They found that luteolin did this by affecting how one protein, which switches on the genes that produce inflammatory molecules like IL-6, binds to DNA.

The researchers found that when they gave mice luteolin in their drinking water, it reduced the production of IL-6 in the blood and in certain areas of the brain when the mice were exposed to LPS.

What interpretations did the researchers draw from these results?

The researchers concluded that “luteolin inhibits LPS-induced IL-6 production in the brain” and that it might be useful for reducing inflammation in the brain.

What does the NHS Knowledge Service make of this study?

This laboratory study gives some indication of the effects of luteolin on one molecule involved in the inflammatory response in the brain in mice. However, many molecules are involved in inflammation, and it is not yet known whether luteolin has an effect on these molecules, or on the symptoms or consequences of inflammation, such as fever and damage to organs such as the brain.

It is too early to know whether luteolin will have any effect on humans, and whether it would be helpful in treating or preventing brain inflammation or other brain conditions.

Sir Muir Gray adds...

If I had brain damage, I would try anything that might do good and will do no harm, even celery.